The invention relates to a fuel preheater, especially for use in diesel engines of motor vehicles, in which the fuel as the first fluid medium is warmed by absorbing heat from a second fluid medium of higher temperature, and in which the two media are carried through the preheater in separate passages.
Fuel preheaters of the above-described kind are known and serve especially to prevent the segregation of paraffin crystals from diesel fuel at low temperatures by heating the fuel preferably by thermal energy originating from the cooling water circuit. Known preheaters have a number of disadvantages, which are encountered singly and sometimes also in combination. The following disadvantages in particular are to be mentioned: bulky construction and therefore more difficult installation where little space is available in a motor chamber, danger of the two media becoming mixed in the case of leakage, complex construction involving a large number of parts and hence high manufacturing costs, heavy weight, and inefficient thermal design resulting in low efficiency.
The problem therefore presents itself of creating a fuel preheater of the kind described above, which will avoid the described disadvantages, will be compact, light and reliable in operation, will have a high efficiency, and will be economical to manufacture and install.